Nondestructive deep-level diagnostic method for semi-insulating materials

An original nondestructive method for the local deep-level diagnostics of semi-insulating materials is discussed. The method, called deep-level relaxation optoelectronic spectroscopy (DLROS), is based on the contactless recording of relaxation processes of the electron-hole and trap systems. It can be used to determine the type, energy, and capture cross section of deep energy centers and to establish their distribution in a wafer for integrated-circuit applications. The DLROS method is effective for the production input, interim (between operations), and output monitoring of substrates and GaAs structures. Unlike DLTS, it does not require the fabrication of measurement electrodes on samples.